Last summer, Boston suffered more than 20 inches of rain. This record, set when the weather service began rainfall records in 1872, was only surpassed in 1955 when two hurricanes brought 25 inches of rain.
An estimated 1.5 billion gallons of water sluiced off the land, overwhelmed sewage treatment facilities, and surged raw sewage into the Merrimack River. This amount is three times more than untreated sewage that goes into the river in a typical year. The drinking water was polluted for 500,000 people living in Lowell, Methuen, Andover, Tewksbury, and Lawrence.
Drought depleted municipal water supplies, and rivers ran nearly dry during the summer of 2022. The damages were not due to climate change. The problem is that we have turned our verdant landscapes into hardscapes where water rushes instead of infiltrating the ground. We have lost soil that holds water, pumped out groundwater, and depleted aquifers. During dry summers, rivers are no longer recharged with cool groundwater, coldstream fish and smaller trees with shallow roots die.
Informed by our understanding of how ecosystems work, it’s high time for Massachusetts to act to restore the land by keeping water local for plants to grow and heal the land. Let’s begin at home with lawn care. We are told to spread one pound of fertilizer per thousand square feet five times yearly. Fertilizer is mostly nitrogen with phosphorus. The applied nitrogen kills microbes and beneficial nematodes. Soil particles no longer adhere together, and soil structure deteriorates. An abundance of fertilizer is washed into our waterways to cause harmful algal blooms. Water is fowled, and beaches are closed. Fertilizer nitrogen often ends up as nitrate or nitrite. The link between nitrate and cancer is so strong that it is not safe to drink the water due to excessive nitrate levels in some locations.
Without quick-release fertilizer, the tips of thirsty roots no longer bake at the surface and go down to open the soil. Plants draw down 3.67 tons of carbon dioxide to manufacture one ton of carbohydrates (sugars and lipids). Grasses are the champions at pushing half of the liquid carbon out of root tips to feed the soil. Most plants retain two-thirds to build their biomass.
A natural lawn in Massachusetts can build an inch of soil in a year. Organic carbon acts as sticky springs holding mineral grains far apart, leaving passages for air and water. Four inches of soil can hold seven inches of rainwater to protect homes from stormwater damage and enable photosynthesis that builds more soil.
In Springfield, Massachusetts, 16 lawns that were not fertilized or watered had 63 plant species; 30% of the spontaneous plant species were native to North America, and 93 species of bees. In urban areas, fertilizer-free lawns support pollinators, increase wildlife diversity, and may reverse regional bee population declines.
A proposed Slow Water Carbon Offset Fund, established with state money and private donations, would pay residents who pledge not to apply quick-release fertilizer $1 a square foot of lawn up to $1,000. The fund would incentivize residents to restore degraded land with a new lawn because building more soil is in our interests.
There are more than 2,000 square miles of residential lawns in Massachusetts. An inch of soil would add 232,320,000 tons of organic carbon. Grass photosynthesis would pull 852,614,400 tons of carbon dioxide out of the atmosphere. An inch deep of 2,000 square miles of soil will hold 6.5 million gallons of water. Two thousand square miles of soil four inches deep holds 25.8 million gallons. An acre with six-inch deep soil holds approximately 38,445 gallons of water. Research indicates that if we can slow down water to keep more at home, we can reduce the rise in sea level by 25%.
The Fund would also incentivize property owners to install green infrastructure by administering a grant program modeled on Maryland’s Stormwater Management-Watershed and Restoration Program. Funds would be distributed to residents installing rainscapes. Property owners can choose from rain barrels, green roofs, permeable pavers that provide a hard surface that can also infiltrate water, a native plant garden designed to absorb water, and Miyawaki forests.
In Cambridge, Massachusetts, a couple recently planted a Miyawaki forest in the 600-foot square plot between their house and the sidewalk. About 40 native species of woody plants were selected, representing all stages of forest development from early successional, sumac, aspen, and birch to mid-succession cherry, dogwoods, elm, and climax oaks, maples, ash, and beech, plus small evergreens white pine, pitch pine, fir and spruce, and groundcover blueberries and spicebush. This great diversity increases the vigor of all plants, with a vast array of bacteria generating different enzymes offered to all plants via the mycorrhizal web of fungi and plant roots.
The Let Forest Grow Carbon Offset Fund would complete the restoration of landscapes by paying the value of timber harvests to leave the tree standings on state lands. On private lands, where 10-year woodlot management plans are in place, the Fund would pay landowners the value of their timber harvest and let trees keep growing.
Eighty-year-old forests store over twice as much carbon as 40-year-old forests. The largest one percent of trees are responsible for 30% of the carbon sequestered. Bark-covered wood stores water, and trees release water through stomata when it’s hot. The water vapor evaporates and cools. Trees again release water vapor that condenses to warm the microclimate at the darkest, coldest hour before dawn.
Old-growth forests release the most bacteria, fungi, and pollen that float in the air. Water vapor nucleates around these particles to form cumulous clouds that reflect heat to cool the atmosphere. Cloud formation causes a decrease in atmospheric pressure. The pressure gradient pulls water vapor in from the ocean to the forest. When old trees are removed, the biotic pump ceases to operate, and more water vapor stays over the ocean to power stronger hurricanes that dump record rainfalls.
Two carbon offset funds, one that invests in storing organic carbon and holding water in soils and the other pays timber harvest revenue to keep trees standing, would pay dividends to everyone. What happens in soils and forests does not stay in soils and forests. Entire watersheds and the climate benefit; even the nests we build called cities are better off.